. . "(astronomy) an arbitrarily fixed date that is the point in time relative to which information (as coordinates of a celestial body) is recorded"@en-us . . . . . "114431458"@en-us . . "epoch"@en-us . "15296687-n"^^ . . "0"^^ . . . "date of reference"@en-us . "115296687"^^ . "0"^^ . . "epoch"^^ .